#include <CoreFoundation/CoreFoundation.h>
#include <CommonCrypto/CommonDigest.h>
#include <CommonCrypto/CommonDigestSPI.h>
#include <CommonCrypto/CommonRSACryptor.h>
#include <CommonNumerics/CommonBaseXX.h>
#include <stdio.h>
#include <sys/types.h>
#include <dirent.h>
#include <string.h>
#include <unistd.h>
static const char* kPublicManifestKeyData = "MIIBCgKCAQEA7eev+hip+8Vg1kj/q4qnpN37X8vaKZouAyoXZ6gy+2D2wKxR0KORuV9bCFkcyT+LST/Rhn+64YNSZ7UvkQRlU34vZcF7FWuPfEbLGcCG7e1hlshHVUUah+07Qyu82f6OAg8PBFvYwvZHZMcXlvZJQjdNtbIORQfdlrGpRN1C6xKfbX6IKE9LViGQJmljdRuaK/SxmKyMsLfsTCzh+6yxMpPtY75PuSfrVcDSlGhr108QfP5n2WQ9frtyFgdowlXr/kECWSUrj8qDk1JymVd2ZyF3dlTWdzSO17vDt6caQyjQmTyGrGRGOM6THSq9mB/fv1Q5gxEfIIb8SejTvu4GSwIDAQAB";
static int ValidateFilesInDirectory(const char* dir_path, int num_files, const char * files[])
{
int result = 0; DIR* dirp = NULL;
struct dirent* dp = NULL;
dirp = opendir(dir_path);
if (NULL == dirp)
{
return -1;
}
for (int iCnt = 0; iCnt < num_files; iCnt++)
{
int name_length = (int)strlen(files[iCnt]);
int found = 0;
while (NULL != (dp = readdir(dirp)))
{
if (dp->d_namlen == name_length && 0 == strcmp(dp->d_name, files[iCnt]))
{
found = 1;
}
}
if (0 == found)
{
(void)closedir(dirp);
return -1;
}
rewinddir(dirp);
}
(void)closedir(dirp);
return result;
}
static int ReadFileIntoCFDataRef(const char* file_path, CFDataRef* out_data)
{
int result = -1; FILE* infile = NULL;
void* buffer = NULL;
int numbytes = 0;
if (NULL == file_path || NULL == out_data)
{
return result;
}
infile = fopen(file_path, "r");
if (NULL == infile)
{
return result;
}
fseek(infile, 0L, SEEK_END);
numbytes = (int)ftell(infile);
fseek(infile, 0L, SEEK_SET);
buffer = calloc(numbytes, sizeof(char));
if (NULL == buffer)
{
fclose(infile);
return result;
}
fread(buffer, sizeof(char), numbytes, infile);
fclose(infile);
*out_data = CFDataCreate(kCFAllocatorDefault, (const UInt8 *)buffer, numbytes);
free(buffer);
result = (NULL != *out_data) ? 0 : -1;
return result;
}
static int CreateHashForData(CFDataRef cfData, int useSHA1, CFDataRef* out_hash)
{
int result = -1; CCDigestAlgorithm algo = (useSHA1) ? kCCDigestSHA1 :kCCDigestSHA256;
size_t digest_length = (useSHA1) ? CC_SHA1_DIGEST_LENGTH : CC_SHA256_DIGEST_LENGTH;
UInt8 buffer[digest_length];
if (NULL == cfData || NULL == out_hash)
{
return result;
}
*out_hash = NULL;
memset(buffer, 0, digest_length);
if (!CCDigest(algo, CFDataGetBytePtr(cfData), CFDataGetLength(cfData), buffer))
{
*out_hash = CFDataCreate(kCFAllocatorDefault, (const UInt8 *)buffer, digest_length);
}
else
{
return result;
}
result = (NULL == *out_hash) ? -1 : 0;
return result;
}
static int Base64Data(CFDataRef cfData, int for_encoding, CFDataRef* encoded_data)
{
int result = -1; CNEncodings encoding = kCNEncodingBase64;
CNStatus status = kCCSuccess;
CNEncodingDirection direction = (for_encoding) ? kCNEncode : kCNDecode;
unsigned char buffer[1024];
size_t encoded_data_length = 1024;
if (NULL == cfData || NULL == encoded_data)
{
return result;
}
memset(buffer, 0, 1024);
*encoded_data = NULL;
status = CNEncode(encoding, direction, CFDataGetBytePtr(cfData), CFDataGetLength(cfData), buffer, &encoded_data_length);
if (kCCSuccess == status)
{
*encoded_data = CFDataCreate(kCFAllocatorDefault, (const UInt8 *)buffer, encoded_data_length);
result = (NULL == *encoded_data) ? -1 : 0;
}
return result;
}
static int CreatePropertyListFromData(CFDataRef prop_data, CFTypeID output_type, CFTypeRef* plistRef)
{
int result = -1; CFPropertyListRef aPlistRef = NULL;
CFPropertyListFormat list_format = kCFPropertyListXMLFormat_v1_0;
CFErrorRef error = NULL;
if (NULL == prop_data || NULL == plistRef)
{
return result;
}
*plistRef = NULL;
aPlistRef = CFPropertyListCreateWithData(kCFAllocatorDefault, prop_data, 0, &list_format, &error);
if (NULL != error || NULL == aPlistRef)
{
if (NULL != error)
{
CFRelease(error);
}
return result;
}
if (CFGetTypeID(aPlistRef) != output_type)
{
CFRelease(aPlistRef);
return result;
}
*plistRef = aPlistRef;
result = (NULL == *plistRef) ? -1 : 0;
return result;
}
static int TearOffSignatureAndHashManifest(CFDictionaryRef manifestDict, CFDataRef* signature, CFDataRef* manifest_data)
{
int result = -1;
CFMutableDictionaryRef new_manifest_dict = NULL;
CFStringRef sig_data_str = NULL;
CFDataRef sig_data = NULL;
CFDataRef prop_list = NULL;
CFDataRef decoded_sig_data = NULL;
if (NULL == manifestDict || NULL == signature || NULL == manifest_data)
{
return result;
}
*signature = NULL;
*manifest_data = NULL;
new_manifest_dict = CFDictionaryCreateMutableCopy(kCFAllocatorDefault, CFDictionaryGetCount(manifestDict), manifestDict);
sig_data_str = (CFStringRef)CFDictionaryGetValue(new_manifest_dict, CFSTR("Signature"));
if (NULL == sig_data_str)
{
CFRelease(new_manifest_dict);
return result;
}
sig_data = CFStringCreateExternalRepresentation(kCFAllocatorDefault, sig_data_str, kCFStringEncodingUTF8, 0);
if (NULL == sig_data)
{
CFRelease(sig_data_str);
CFRelease(new_manifest_dict);
return result;
}
if (Base64Data(sig_data, 0, &decoded_sig_data))
{
CFRelease(sig_data);
CFRelease(new_manifest_dict);
return result;
}
*signature = decoded_sig_data;
CFDictionaryRemoveValue(new_manifest_dict, CFSTR("Signature"));
prop_list = CFPropertyListCreateXMLData (kCFAllocatorDefault, new_manifest_dict);
CFRelease(new_manifest_dict);
if (NULL == prop_list)
{
return result;
}
(void)CreateHashForData(prop_list, 1, manifest_data);
result = (NULL == *manifest_data) ? -1 : 0;
return result;
}
static int GetPublicManifestKey(CCRSACryptorRef* key_ref)
{
int result = -1;
CFStringRef encoded_key_data_str = NULL;
CFDataRef encoded_key_data_str_data = NULL;
CFDataRef decoded_key_data = NULL;
CCCryptorStatus ccStatus = kCCSuccess;
if (NULL == key_ref)
{
return result;
}
*key_ref = NULL;
encoded_key_data_str = CFStringCreateWithCString(kCFAllocatorDefault, kPublicManifestKeyData, kCFStringEncodingUTF8);
if (NULL == encoded_key_data_str)
{
return result;
}
encoded_key_data_str_data = CFStringCreateExternalRepresentation(kCFAllocatorDefault, encoded_key_data_str, kCFStringEncodingUTF8, 0);
if (NULL == encoded_key_data_str_data)
{
CFRelease(encoded_key_data_str);
return result;
}
CFRelease(encoded_key_data_str);
if (Base64Data(encoded_key_data_str_data, 0, &decoded_key_data))
{
CFRelease(encoded_key_data_str_data);
return result;
}
CFRelease(encoded_key_data_str_data);
ccStatus = CCRSACryptorImport(CFDataGetBytePtr(decoded_key_data), CFDataGetLength(decoded_key_data), key_ref);
CFRelease(decoded_key_data);
if (kCCSuccess != ccStatus)
{
*key_ref = NULL;
}
else
{
result = 0;
}
return result;
}
static int ValidateSignature(CFDataRef signature, CFDataRef data)
{
int result = -1;
CCRSACryptorRef key_ref = NULL;
CCCryptorStatus ccStatus = kCCSuccess;
if (NULL == signature || NULL == data)
{
return result;
}
if (GetPublicManifestKey(&key_ref))
{
return result;
}
const void *hash_data_ptr = CFDataGetBytePtr(data);
size_t hash_data_len = CFDataGetLength(data);
const void* sig_data_pre = CFDataGetBytePtr(signature);
size_t sig_dat_len = CFDataGetLength(signature);
ccStatus = CCRSACryptorVerify(
key_ref,
ccPKCS1Padding,
hash_data_ptr,
hash_data_len,
kCCDigestSHA1,
0,
sig_data_pre,
sig_dat_len);
CCRSACryptorRelease(key_ref);
result = (kCCSuccess == ccStatus) ? 0 : -1;
return result;
}
int ValidateAsset(const char* asset_dir_path, unsigned long current_version)
{
const char* files[] =
{
"certs.plist",
"distrusted.plist",
"EVRoots.plist",
"Manifest.plist",
"revoked.plist",
"roots.plist"
};
int num_files = (sizeof(files) / sizeof(const char*));
int iCnt = 0;
const char* file_name = NULL;
char wd_buf[1024];
const char* current_working_directory_path = getcwd(wd_buf, 1024);
CFDataRef file_data = NULL;
CFDataRef hash_data = NULL;
CFDataRef encoded_hash_data = NULL;
CFStringRef manifest_hash_data_str = NULL;
CFDataRef signature_data = NULL;
CFStringRef key_name = NULL;
CFDictionaryRef manifest_dict = NULL;
CFNumberRef manifest_version = NULL;
CFStringRef encoded_hash_str = NULL;
CFDataRef manifest_data = NULL;
unsigned long manifest_verson_number;
int iResult = -1;
if (NULL == asset_dir_path)
{
return iResult;
}
if (ValidateFilesInDirectory(asset_dir_path, num_files, files))
{
return iResult;
}
if (chdir(asset_dir_path))
{
return iResult;
}
if (ReadFileIntoCFDataRef("Manifest.plist", &file_data))
{
(void)chdir(current_working_directory_path);
return iResult;
}
if (CreatePropertyListFromData(file_data, CFDictionaryGetTypeID(), (CFTypeRef *)&manifest_dict))
{
CFRelease(file_data);
(void)chdir(current_working_directory_path);
return iResult;
}
CFRelease(file_data);
for (iCnt = 0; iCnt < num_files; iCnt++)
{
file_name = files[iCnt];
if (!strcmp("Manifest.plist", file_name))
{
continue;
}
if (ReadFileIntoCFDataRef(file_name, &file_data))
{
CFRelease(manifest_dict);
(void)chdir(current_working_directory_path);
return iResult;
}
if (CreateHashForData(file_data, 0, &hash_data))
{
CFRelease(file_data);
CFRelease(manifest_dict);
(void)chdir(current_working_directory_path);
return iResult;
}
CFRelease(file_data);
if (Base64Data(hash_data, 1, &encoded_hash_data))
{
CFRelease(hash_data);
CFRelease(manifest_dict);
(void)chdir(current_working_directory_path);
return iResult;
}
CFRelease(hash_data);
encoded_hash_str = CFStringCreateFromExternalRepresentation(kCFAllocatorDefault, encoded_hash_data, kCFStringEncodingUTF8);
if (NULL == encoded_hash_str)
{
CFRelease(encoded_hash_data);
CFRelease(manifest_dict);
(void)chdir(current_working_directory_path);
return iResult;
}
CFRelease(encoded_hash_data);
key_name = CFStringCreateWithCString(kCFAllocatorDefault, file_name, kCFStringEncodingUTF8);
if (NULL == key_name)
{
CFRelease(encoded_hash_str);
CFRelease(manifest_dict);
(void)chdir(current_working_directory_path);
return iResult;
}
manifest_hash_data_str = (CFStringRef)CFDictionaryGetValue(manifest_dict, key_name);
if (NULL == manifest_hash_data_str)
{
CFRelease(key_name);
CFRelease(encoded_hash_str);
CFRelease(manifest_dict);
(void)chdir(current_working_directory_path);
return iResult;
}
CFRelease(key_name);
if (!CFEqual(encoded_hash_str, manifest_hash_data_str))
{
CFRelease(encoded_hash_str);
CFRelease(manifest_dict);
(void)chdir(current_working_directory_path);
return iResult;
}
CFRelease(encoded_hash_str);
}
manifest_version = (CFNumberRef)CFDictionaryGetValue(manifest_dict, CFSTR("Version"));
if (NULL == manifest_version)
{
CFRelease(manifest_dict);
(void)chdir(current_working_directory_path);
return iResult;
}
if (!CFNumberGetValue(manifest_version, kCFNumberLongType, &manifest_verson_number))
{
CFRelease(manifest_version);
CFRelease(manifest_dict);
(void)chdir(current_working_directory_path);
return iResult;
}
CFRelease(manifest_version);
if (manifest_verson_number < current_version)
{
CFRelease(manifest_dict);
(void)chdir(current_working_directory_path);
return iResult;
}
if (TearOffSignatureAndHashManifest(manifest_dict, &signature_data, &manifest_data))
{
CFRelease(manifest_dict);
(void)chdir(current_working_directory_path);
return iResult;
}
iResult = ValidateSignature(signature_data, manifest_data);
CFRelease(signature_data);
CFRelease(manifest_data);
CFRelease(manifest_dict);
(void)chdir(current_working_directory_path);
return iResult;
}